Round Ductwork Installation Tips

Installing ductwork isn't hard when you have these expert tips.

Working with round ducts

Whether you’re adding new heat runs in a basement or changing the layout of an existing HVAC system, you’ll probably be working with round metal duct pipe. We invited Bob Schmahl to give us a few pointers. Bob’s been a tin bender for more than 40 years. He insists he still doesn’t know everything about ductwork, but we weren’t convinced. These tips should help make your next job run that much smoother.

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Install dampers at the registers

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Don't peel off old tape

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Bob's not a fan of flexible duct

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Assemble the pipe like a zipper

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A hole cutter works great in tight spots

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Overlap butt joints with draw band connectors

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Caulk the take-offs

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Leave backing on the tape

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Make two marks for cutting

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Use support brackets and three screws

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Move one ring at a time

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Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • Caulk gun
  • Cordless drill
  • Safety glasses
  • Utility knife
  • Tin snips

In addition you will need a hole cutter, a right angle drill or right angle attachment and leather gloves.

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

  • Damper
  • Foil tape
  • Draw band connector
  • Silicone caulk
  • 1-in. galv. zip screws for metal
  • Adjustable elbows
  • Ductwork